​The PT-91Twardyis a Main Battle Tank in service with the Polish Armed Forces that entered service in 1995. It is an upgraded version of the Russian T-72. Changes include a new dual-axis stabilized fire-control system, reactive armor, a more powerful engine, transmission and new automatic loader. Unlike many other T-72 upgrades the Polish Army PT-91s are upgraded using elements created almost exclusively by domestic companies.

The first 20 initial production vehicles were delivered to Polish Land Forces in 1993–1994 with another 78 full-scale production vehicles delivered 1995–1997, 135 modernized T-72M1 tanks (made in late 80s) delivered 1998–2002. Both new and modernized tanks have the same combat capabilities. Depending exact configuration Polish Army uses PT-91s in 3 variants PT-91, PT-91M and PT-91MA1.